Tests Accessibility.getChildAXNodes
After getFullAXTree:
RootWebArea
main
article
Iframe
After getChildAXNodes:
RootWebArea
main
article
heading "Article"
paragraph
Iframe
getChildAXNodes iframe:
RootWebArea
main
article
heading "Article"
paragraph
Iframe
RootWebArea "Iframe with accessible name"
heading "accessible name"